Clamping arrangement for pipes



Dec. 20, 1966 s. SCHIANSKY CLAMPING ARRANGEMENT FOR PIPES 2 Sheets-Sheet1 Filed Feb. 1, 1965 Dec. 20, 1966 s. SCHIANSKY 3,292,956

CLAMPING ARRANGEMENT FOR PIPES Filed Feb. 1, 1965 2 Sheets-Sheet 2United States Patent "ice 3,292,956 CLAMPING ARRANGEMENT FOR PIPESSiegfried Schiansky, Schlierseestrasse 71, Munich 9, Germany Filed Feb.1, 1965, Ser. No. 429,426 8 Claims. (Cl. 287-58) The present inventionrelates to an arrangement for clamping together tubular elements adaptedto be mutually slidable and rotatable, and more particularly relates toa clamping arrangement for tubularly shaped legs of camera stands,especially of tripods or similar apparatus.

For purposes of clamping mutually slidable and rotatable tubularelements a number of different constructions are known already in theprior art. They are based for the most part in principle on actuating,with the aid of cams or the like, some suitable expanding means duringrotation of one of the tubular elements whereby a clamping effect isthen achieved by frictional engagement.

All of the rotational clamping arrangements known heretofore involvingtubular elements have the serious disadvantage that the clamping effectis based always exclusively only on a force-locking connection of two ofthe tubular elements which is more' or less effective depending on thefriction between a tubular element and the respective clamping parts.

In order to avoid this disadvantage, the present invention proposes withthe use of a clamping sleeve between the two tubular elements, that theclamping sleeve is form-lockingly connected with one tubular elementforexample, by teeth at the end face thereofand that additionally byrotation of the other tubular element, a force-locking connection of thetwo tubular elements with each other is achieved by way of cams or thelike.

According to a further development of the present invention, theform-locking connection between the clamping sleeve and the one tubularelement is established in that one or several projections or noseportionsfor example, in the form of pressed-in or pressed-out portionsin the walls of the tubular elements-are provided in the one tubularelement with which come into engagement the teeth at the end face of theclamping sleeve. The engagement thereby takes place according to thepresent invention in such a manner that always a small gap remainsbetween the points of the teeth at the clamping sleeve and at theprojections provided in the tubular element. In conjunction with thefurther measure according to the present invention, to constructconically the end of the tubular element at which are accommodated theprojections necessary for the form-locking engagement, the points of theclamping sleeve teeth are caused to extend onto a conically taperingannular gap and are wedged therein without play. A connection of the twotubular elements with each other completely free of wobble is createdthereby, notwithstanding the play normally necessary and dependent ontolerances.

The tubular connection according to the present invention furtherdistinguishes itself by the fact that the locations of the force-lockingconnection and the form-locking abutment, which are both locatedapproximately at opposite ends of the clamping sleeve, have a relativelylarge spacing from one another so that a large clamping base is producedthereby. The fact that the prevailing length of the clamping base can besuitably determined by a choice in the length of the clamping sleeve isof additional advantage.

According to a still further proposal in accordance with the presentinvention, differing from the construction described so far, theapplication of a simultaneous formand force-locking connection takesplace in such a manner that an inwardly directed narrow web is arrangedat the outer tubular element or an outwardly directed narrow PatentedDec. 20, 1966 web is arranged at the inner tubular element which extendsover the entire length of the tubular element. For purposes of achievinga form-locking connection, the longitudinal slot of the rotatablyarranged clamping sleeve thereby engages into this web. The particularadvantage accruing to this is that a form-locking connection of the twomutually telescopically slidable tubular elements is achieved in everydesired pulled-out position or extended and the telescopicallyextensible tubular elements can therefore be clamped with each other inevery such position.

By the application of a simultaneous form and forcelocking connectionrealized in accordance with the proposals of the present invention,there is achieved, in conjunction with the further measures according tothe present invention, with simple means an absolutely reliableconnection of two mutually extensible or telescopic tubular elements notattained heretofore in its effectiveness.

The present invention may be applied to the connection of all suitabletelescopic mutually slidable and rotatable tubular elements; preferably,however, they are suited for tubularly shaped telescoping legs of standsor tripods for photographic apparatus, projection tables or the like. Ofparticular advantage is the space-saving construction which makespossible an application of the present invention even with smaller tubediameters. Additionally, with stand legs having several telescopic partseach, there results the advantage from the present invention that duringtelescopic retraction of the individual parts, that is, when sliding theparts one into the other, no length useful for the extension is lost.

Accordingly, it is an object of the present invention to provide aclamping arrangement for mutually slidable and rotatable tubularelements, particularly telescopic legs of stands for photographicapparatus, which by extremely simple means obviate the aforementionedshortcomings encountered with the prior art constructions.

Another object of the present invention resides in the provision of aclamping arrangement for mutually slidable and rotatable telescopictubular elements which assures simultaneous forceand form-lockingengagement of the various parts.

A further object of the present invention resides in the provision of aclamping arrangement for mutually sildable and rotatable tubularelements which is not only extremely simple in construction, easy tomanufacture, and low in cost but at the same time assures a reliableclamping in every position of the telescoping parts thereof.

Still a further object of the present invention resides in a provisionof a clamping arrangement for clamping mutually slidable and rotatabletubular elements which assures a safe connection between the parts,completely free of play that would endanger the rigidity of the stand.

Another object of the present invention resides in the provision of aclamping arrangement for mutually slidable -and rotatable tubularelements which permits a clamping base of any desired length, that canbe readily selected at the will of the designer.

A still further object of the present invention resides in the provisionof a clamping arrangement for telescopic tubes of the type describedabove which achieves an absolutely reliable connection between the partswith an effectiveness unattainable heretofore.

Still a further object of the present invention resides in the provisionof a clamping arrangement of the type described above which is ofspace-saving construction and permits application thereof to tubularelements of even relatively very small diameter.

These and further objects, features and advantages of the presentinvention will become more obvious from the following description whentaken in connection with the accompanying drawing which shows, forpurposes of illusn-n of FIGURE 1,

FIGURE 3 is an axial longitudinal cross-sectional view of a modifiedembodiment of a clamping arrangement in accordance with the presentinvention in which the clamping sleeve is brought into form-lockingconnection with the outer tubular element,

FIGURE 4 is a cross-sectional view taken along line IV-IV of FIGURE 3, vFIGURE is an axial cross-sectional view through a still further modifiedembodiment of a clamping arrange ment in accordance with the presentinvention having a form-locking connection and provided with anoutwardly directed web at the inner tubular element.

FIGURE6 is a cross-sectional view taken along line VIVI of FIGURE 5,

FIGURE 7 is an axial longitudinal cross-sectionalview through stillanother modified embodiment of the clamping arrangement in accordancewith the present invention having a form-locking connection and providedwith an inwardly directed web at the outer tubular element, and

FIGURE 8 is a cross-sectional view taken along line VIIIVIII of FIGURE7.

Referring now to the drawing wherein like reference numerals are usedthroughout the various views to designate like parts, and moreparticularly to FIGURES l and 2, a clamping sleeve 3 is arranged betweenthe inner tubular element 1 and the outer tubular element 2 which aremutually slidable and rotatable. The clamping sleeve 3 is securedagainst movement in the longitudinal direction at the outer tubularelement 2 and is adapted to be rotated through a predetermined angle.The clamping sleeve 3 is provided at one end with an end-face toothing4. Nose portions or projections 5 having an acute angle are arranged atthe inner tubular element 1, preferably in the form of tabs, which arepressed outwardly of the tube wall. The projections 5 point with theacute angle thereof toward the end-face toothing 4 at the sleeve 3 andduring extension of the inner tubular element into its end position, theprojections 5 engage into the teeth 4 and thus establish a form-lockingconnection between the sleeve 3 and the inner tubular element 1. Asuitable number of projections 5 may be provided, distributed along thecircumference, appropriately three projections 5 being shown in thepresent case.

At the end of the clamping sleeve 3 opposite the endface toothing 4,three springy tongues 6 are provided, for example, distributed over thecircumference; cam tracks or cams 7 coordinated to the tongues 6 areaccommodated at the outer tubular element 2. During a rotationalmovement of the tongues 6 in the direction of the cams 7 or vice versa,the tongues 6 are pressed into abutment against the inner tubularelement 1 and thus a forcelocking clamping connection is establishedbetween the two tubular parts. The cams 7 may be advantageouslypressed-in into the walls of the tubular element 2.

The tongues are punched out of the sleeve 3 and, in conjunction witheach tongue 6, an aperture or cutout 8 may be provided into whichextends a respective cam 7, whereby the clamping sleeve 3 is secured inits position in the axial direction on the tubular element 2. Themanufacture of the clamping sleeve 3 can take place thereby in a simpleand inexpensive manner, for example, such that the sleeve 3 is rolledfrom a correspondingly semi-finished flat or plate into a subsequentlyslotted sleeve. In order to obviate any possibility of the sleeve 3slipping out of the outer tubular element 2, the lower edge of the endface of the latter element may be slightly pressed-in at a few placesalong the inner circumference thereof.

The form-locking connection between the projections 5 and the end teeth4 takes place according to the present invention in such a manner that asmall gap always remains between the points of the teeth 4 and theprojections 5. In conjunction with the further measure proposed inaccordance with the present invention that the end 9 of the inner tube 1is enlarged conic-ally in theoutward direction, i.e., is flaredconically in the outward direction, the points of the teeth 4 extendinto the coni-.

ca'lly tapering annular gap and are wedged there-in Without play.Simultaneously during rotation in the clamping direction the clampingtongues 6 at the sleeve 3 are expanded.

In the clamped condition, there is thus created by the present inventiona clamping base A whose length is determined by the distance of theplane of the expandable clamping means 6, 7 to the end of the end-facetoothing 4.

The clam-ping base A may be suitably determined by the respective lengthof the clamping sleeve 3 and in every case a connection of the twotubular elements with each other may be achieved which is absolutelyfree of wobble.v

The application in accordance with the present inven- I tion of asimultaneous formand force-locking connection entails the considerableadvantage that the clamping connection is not dependent on the magnitudeand effect of a frictional en-gagement as initiating force, but insteada form-locking engagement precedes the exclusively forcelocking clampingconnection. locking engagement of the clamping sleeve 3 with the tubularelement 1, a fully effective expanding clamping action is achieved inevery case A clamping arrangement is illustrated in FIGURES 3 and 4which is the reverse from that of FIGURES 1 and 2. The end teeth 14 atthe sleeve 13 engage in this, embodiment, for the establishment of aform-locking connection, into projections 15 which are pressed-in intothe outer tubular element 12. The expanding clamping action of thesleeve 13 is etfectuated by way of springy tongues 16 by means of cams17 at the inner tubular element 11. The 'lower end 19 of the outertubular ele-,

ment 12 is contracted conically for purposes of securing the sleeve 13without play. The points of the teeth 14 l are wedged securely withoutplay within the conical annular gap at the tube end 19. The function ofthe connection is thereby the same as in the embodiment explained anddescribed in connection with FIGURES 1 and 2. The clam-ping of theindividual telescopic tubes of a tripod leg thereby takes place in asimple manner such that the largest tube is held fast, then all of theother tubes are 1 completely pulled out and by rotation of the lowermostsmallest tube, simultaneously all of the pulled-out or;

extended tubes are clamped. As shown in FIGURES 1 and 3 the connectionbetween the outermost tubular members 22 and outer tubular member 2,FIGURE ,1 and member 12, FIGURE 3 is effected by conventional detentmeans in the form of selectively manually releasable spring detentmembers '22 engaging in apertures in the members 2 and 12, theseapertures being connected by groove means for guiding the detent members22 upon 7 endwise movement of the members 2 =and 12. The detent meansjust referred to is old and well known, does not form part of applicantsinvention and is not being claimed.

For purposes of disengagement of the clamped tubular counter-toothing23. The disengagement of the clamped tu-bu'lar parts of a tripod leg canthereby take place in an advantageous manner such that the outer tubularelement 2 is held fast and the next smaller tubular element is unclampedby rotation in the counter-clamping direction By reason of the formandis then pushed-in or retracted. When this tubular element has beencompletely pushed home, it locks with its crown toothing 20 in the teeth23 within the closure part 21 and thereupon the next smaller tubularelement can be unclamped and retracted or pushed-in, which in turn lockswith the crown toothing 20 thereof in the counter-toothing 23; in asimilar manner all of such other telescopic tubes as may be desired maybe unclamped and retracted or pushed in whereby only the outer tubularelement 2 has to be held fast.

FIGURES 5 to 8 illustrate another proposal according to the presentinvention for the realization of a form- 'locking connection byreference to two further embodiments; the force-locking connectionthereby takes place in the same manner as in the embodiments accordingto FIGURES 1 to 4.

The form locking connection 'between the sleeve 30 and the inner tubularelement 31 takes place in the embodiment of FIGURES 5 and 6 in such amanner that an outwardly directed, small web 32 is arranged at the innertubular element 31, which extends over the entire length of the tube.For purposes of achieving a form-locking connection, the longitudinalslot 33 constituted by the clamping sleeve 30 engages with the web 32.

In the embodiment according to FIGURES 7 and 8 there is arranged for theform-locking connection at the outer tubular element 32 in an inwardlydirected small web 36 which also extends over the entire length of thetube and engages in the longitudinal slot 38 constituted by the clampingsleeve 37.

With these constructions of the form-locking connection, there isachieved the advantage that in every extended position a form-lockingengagement exists and the tubular elements can thus be clamped to eachother in any desired position.

The force-locking clamping connection as well as the position-securingmeans of the clamping sleeve thereby takes place in the same form as hasalready been described in detail in connection with FIGURES 1 to 4. Thespringy tongues 39 at the sleeve 30 and the tongues 40 at the sleeve 37thereby serve for this purpose. The tongues 39 and 40 are therebyexpanded or spread during rotation of the respective tubular element byWay of cams 42 arranged along the periphery of the outer tubular element41 or by way of cams 43 arranged at the inner tubular element 44.

While I have shown and described several embodiments in accordance withthe present invention, it is understood that the same is not limitedthereto but is susceptible of numerous changes and modifications asknown to a person skilled in the art. For example, for purposes of theforce-locking clamping connection, in addition to the constructionsshown in the drawings, also any other known appropriate construction mayfind useful application with the present invention which cause expansionof clamping means upon rotation thereof.

Thus, it is obvious that the present invention is not limited to thedetails shown and described herein but is susceptible of numerouschanges and modifications, and I therefore do not wish to be limited tothe details shown and described herein but intend to cover all suchchanges and modifications as are encompassed by the scope of theappended claims.

I claim:

1. An arrangement for clamping two mutually slidable and rotatabletubular elements especially for photographic apparatus, comprising atleast two tubular members arranged for telescopic movement relative toone another,

a clamping sleeve member rotatably disposed between said telescopictubular members, said clamping sleeve member being also secured in theaxial direction in position between said telescopic tubular members,

interengageable male and fem-ale locking means, one of said lockingmeans being disposed on the first of said telescopic tubular members andthe other of said locking means being disposed on said clamping sleevemember in such a position as to be engaged or released upon relativeaxial movement between said 5 first telescopic tubular member and saidclamping sleeve member, said male and female locking means being soshaped that when engaged they provide a torque transmitting connectionbetween said clamping sleeve member and said first telescopic tubularmember, and force locking connecting means including at least one camsurface disposed on the other telescoping tubular member and springytongue means disposed on said clamping sleeve member adjacent to saidcam surface, said cam surface and said springy tongue means uponrotation of said clamping sleeve member providing a force-lockingconnection between the two telescopic tubular members.

2. The combination according to claim 1, wherein said first telescopictubular member is the innermost telescopic tubular member and is flaredconically at the upper end thereof and forms together with the other ofsaid two telescopic tubular members a conically tapering annular gap,said torque transmitting connection extending into said gap.

3. The combination according to claim 1, wherein the other telescopictubular member is the outermost of said two telescopic tubular membersand is conically contracted at the lower end thereof and forms togetherwith said first telescopic tubular member a conically tapering annulargap, said torque transmitting connection extending into said gap.

4. An arrangement for clamping two mutually slidable and rotatabletubular elements, especially for tubularly shaped legs of stands forphotographic apparatus, comprising at least two tubular means intelescopic interrelationship,

clamping sleeve means rotatably disposed between said tubular means,said clamping sleeve means being also secured in the axial direction inits position between said tubular means,

form-locking connecting means providing a form-locking connectionbetween one end of said clamping sleeve means and one of said twotubular means,

and force-locking connecting means providing a forcelocking connectionbetween said tubular means upon rotation of the other tubular means,

said form-locking connecting means including at least one projectionnear the upper end of the inner tubular means which extends outwardly,said sleeve means being arranged at the lower end of the outer tubularmeans and being secured in the axial direction on said outer tubularmeans while being rotatable relative thereto through a pre-determinedangle, the upper end face of said sleeve means being provided at leastin part with toothing means adapted to cooperate with said oneprojection,

and said force-locking connecting means including a plurality of springytongue means provided at the other end of said clamping sleeve means,and cam means at the circumference of the outer tubular means forexpanding said tongue means.

65 5. An arrangement for clamping two mutually slidable and rotatabletubular elements, especially for tubularly shaped legs of stands forphotographic apparatus, com prising at least two tubular means intelescopic interrelation- 70 ship,

clamping sleeve means rotatably disposed between said tubular means,said clamping sleeve means being also secured in the axial direction inits position between said tubular means,

form-locking connecting means providing a form-locking connectionbetween one end of said clamping sleeve means and one of said twotubular means,

and force-locking connecting means providing a forcelocking connectionbetween said tubular means upon rotation of the other tubular means,

said form-locking connecting means including at least one projectionnear the lower end of the outer tubular means which projects inwardly,said sleeve means being arranged at the upper end of the inner tubularmeans and being secured in the axial direction on said inner tubularmeans while being rotatable relative thereto through predeterminedangle, the lower end face of said sleeve means being provided at leastpartly with toothing means adapted to cooperate with said oneprojection,

said force-locking connecting means including a plurality of tonguemeans at the other end of said sleeve means along the circumferencethereof, and cam means arranged along the circumference of said innertubular means for expanding said tongue means.

6. An arrangement for clamping two mutually slidable and rotatabletubular elements especially for tubularly shaped legs of stands forphotographic apparatus, comprising at least two tubular means intelescopic interrelationship,

clamping sleeve means rotatably disposed between said tubular means,said clamping sleeve means being also secured in the axial direction inits position between said tubular means,

form-locking connecting means providing a form-locking connectionbetween said clamping sleeve means and one of said two tubular means,

and force-locking connecting means providing a forcelocking connectionbetween said tubular means upon rotation of the other tubular means,

each extensible tubular means being provided at the upper end facethereof with cr-own toothing means, a closure part at the outer tubularmeans and provided with countertoothing means, the crown toothing meansat the end face of a respective tubular means engaging in the fullyretracted position thereof with said counter-teething means.

7. An arrangement for clamping two mutually slidable and rotatabletubular elements, especially for tubularly shaped legs of stands forphotographic apparatus comprising two tubular means in telescopicinterrelationship,

clamping sleeve means rotatably disposed between said tubular means,said clamping sleeve means being also secured in the axial direction inits position between said tubular means,

form-locking connecting means providing a form-locking connectionbetween said clamping sleeve means and one of said two tubular means,

and force-locking connecting means providing a forcegaging in said slotfor establishing a form-locking connection,

said force-locking means including a plurality of springy tongue meansat each end of the clamping sleeve means and cam means at one of saidtubular means for expanding said tongue means.

8. An arrangement for clamping two mutually slidable and rotatabletubular elements, especially for tubularly shaped legs of stands forphotographic apparatus, comprising two tubular means in telescopicinterrelationship, clamping sleeve means rotatably disposed between saidtubular means, said clamping sleeve means being also secured in theaxial direction in its position between said tubular means, form-lockingconnecting means providing a form-locking connection between saidclamping sleeve means and one of said two tubular means, andforce-locking connecting means providing a forcelocking connectionbetween said tubular means upon rotation of the other tubular means,said form-locking connecting means including a radially directed webmeans at one of said tubular means and extending substantially over theentire length thereof, said clamping sleeve means forming efiec-,

tively a longitudinal slot, and said web means engaging in said slot forestablishing a formlocking connection,

said force-locking means including a plurality of springy tongue meansat each end of the clamping sleeve means and cam means at one of saidtubular means for expanding said tongue means,

a cutout portion being provided in said sleeve means in conjunction withsaid tongue means, into which extend the cam'means provided at said onetubular means.

References Cited by the Examiner UNITED STATES PATENTS 2,103,586 12/1937Kitchel et al 285-143 2,391,101 12/1945 Odin.

2,806,723 9/ 1957 Fairclough.

2,884,270 4/ 1959 Carlberg.

2,989,329 6/1961 Noah.

2,991,096 7/ 1961 Davidson.

CARL W. TOMLIN, Primary Examiner. T. A. LISLE, Assistant Examiner.

1. AN ARRANGEMENT FOR CLAMPING TWO MUTUALLY SLIDABLE AND ROTATABETUBULAR ELEMENTS ESPECIALLY FOR PHOTOGRAPHIC APPARATUS, COMPRISING ATLEAST TWO TUBULAR MEMBERS ARRANGED FOR TELESCOPIC MOVEMENT RELATIVE TOONE ANOTHER, A CLAMPING SLEEVE MEMBER ROTATABLY DISPOSED BETWEEN SAIDTELESCOPIC TUBULAR MEMBERS, SAID CLAMPING SLEEVE MEMBER BEING ALSOSECURED IN THE AXIAL DIRECTION IN POSITION BETWEEN SAID TELESCOPICTUBULAR MEMBERS, INTERENGAGEABLE MALE AND FEMALE LOCKING MEANS, ONE OFSAID LOCKING MEANS BEING DISPOSED ON THE FIRST OF SAID TELESCOPICTUBULAR MEMBERS AND THE OTHER OF SAID LOCKING MEANS BEING DISPOSED ONSAID CLAMPING SLEEVE MEMBER IN SUCH A POSITION AS TO BE ENGAGED ORRELEASED UPON RELATIVE AXIAL MOVEMENT BETWEEN SAID FIRST TELESCOPICTUBULAR MEMBER AND SAID CLAMPING SLEEV MEMBER, SAID MALE AND FEMALELOCKING MEANS BEING SO SHAPED THAT WHEN ENGAGED THEY PROVIDE A TORQUETRANSMITTING CONNECTION BETWEEN SAID CLAMPING SLEEVE MEMBER AND SAIDFIRST TELESCOPIC TUBULAR MEMBER, AND FORCE LOCKING CONNECTING MEANSINCLUDING AT LEAST ONE CAM SURFACE DISPOSED ON THE OTHER TELESCOPINGTUBULAR MEMBER AND SPRINGY TONGUE MEANS DISPOSED ON SAID CLAMPING SLEEVEMEMBER ADJACENT TO SAID CAM SURFACE, SAID CAM SURFACE AND SAID SPRINGYTONGUE MEANS UPON ROTATION OF SAID CLAMPING SLEEVE MEMBER PROVIDING AFORCE-LOCKING CONNECTION BETWEEN THE TWO TELESCOPIC TUBULAR MEMBERS.